This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Recently we reported the discovery of a cultivable calicivirus (Tulane virus;TV) isolated from a rhesus macaque. Based on preliminary results that show close similarities between TVs and noroviruses (NVs) in respect to their genetic diversity, epidemiology and histo-blood group antigen (HBGA) binding, plus the availability of in-house reverse genetics system, we are pursuing the development of a TV-based non-human primate surrogate model for human NV gastroenteritis. To support this effort in this study, we developed a qRT-PCR with the objective to enumerate TV RNA load in biological samples through the course of controlled infections of rhesus macaques. A TV was used to inoculate serologically pre-screened juvenile rhesus macaques to induce experimental infection. Additional macaques were inoculated with rhesus- and human-derived NoVs. While TV-inoculated animals developed infection characterized by virus shedding, fever and diarrhea, only asymptomatic infection was noted in NoV-inoculated macaques. A remarkable increase in virus-neutralizing serum antibodies was observed in TV-inoculated animals. Presence of TV antigens was visualized in duodenum biopsies obtained at post-inoculation day three. These results suggest that TV calicivirus might be used to study the pathogenesis and immunity of enteric caliciviruses.